You have all the right steps, but the sequence is not exactly correct.

The buttons are held until the only light still ON is the error light, then let go, then close the cover.

 

Here's the procedure I send out:

1. Power OFF the printer and UN-plug data cable(s).
2. Open the toner access cover.
3. Depress and hold both the Continue and Cancel buttons.
4. With the cover open and both buttons depressed, power ON the unit.
5. Continue to hold the buttons down until the Error light is the only one active.  (you will see the lights cycle several times before this occurs)
6. Close the cover.
7. Done

 

The error you're describing (all lights on, including continue?) means one of two things:

• The current print job is in process of being canceled.

• The printer is resetting to the user default settings.

 If you try the reset procedure I sent and the lights remain on, can you try to display a secondary error code?

(press the continue button-- quickly-- twice)

Ouch..... hope you're still on warranty.

Looks like the system board is toast, P/N is RC446

Thanks for the reply. I tried the steps you suggested but still nothing. As soon as I turn the power on all the lights come on and stay on steady. I held the Continue and Cancel buttons for about 5 minutes and no lights went out. I then tried pushing the Continue button twice quickly and still all lights stayed on, no blinking at all. I even tried directly connecting to computer with a USB cable (instead of network cable) and still have no control over printer. When connected with network cable can't ping or bring up config page. Any other ideas? Thanks.

Measured at J4 of the system board:

 

Ground:      Pins 7, 12, 14

+5vdc:       Pin 13

+24vdc:     Pins 8,9

Yep, your right. Turns out it is either system board or power supply/control unit. Either way it is going to be cheaper to replace. Thanks for you help!

There is no voltage on pin 13.

May want to trace that wire back to the PS and see if there might be an on-board pico fuse or something else amiss.

I wiggled the wires around and checked the voltages again and this time all the readings were what you said they should be (I might not have had my probe on tightly enough the first time) but still all solid lights. We have ordered a 1720dn to replace it. Hope it lasts longer.

Very unusual for the System Board to fail this way.

That's probably all the problem is.

Yea, that is what I thought too, but Dell is running a buy 2 get one free special and we needed a couple of new ones anyway, so just went that route. Thanks for all your help!